ABSTRACT Core C, the Animal and Analysis Core, will support various aspects of all subprojects within the Program Project Grant and is vital to the success of each. The overall aim of the program project is to understand the mechanisms underlying crosstalk between muscle and bone that may contribute to the age related decline in muscle and bone mass and function. The proposed projects will also investigate whether muscle-bone crosstalk mediates some of the beneficial effects of exercise on the musculoskeletal system and if exercise (voluntary wheel running; VWR) can maintain bone-muscle crosstalk during aging. The Specific Aims of this Core are: Aim 1: Perform VWR experiments, soleus (SOL) and extensor digitorum longus (EDL) muscle contractility on VWR and control mice for Projects 1-4 and provide centralized processing and distribution of samples (conditioned media, tissues, serum, etc.) for endpoint determinations by the Projects. Aim 2: Perform SOL and EDL muscle functional testing of mice used in Projects 3-4. Aim 3: Perform microCT analysis to determine bone density and trabecular and cortical bone architectural properties used in Projects 2-4. Aim 4: Perform metabolomic and/or lipidomics analysis of mice from all exercise wheel running or other studies for Projects 1-4. Core C will coordinate microCT imaging, muscle function testing, exercise wheel running and metabolomic/lipidomic profiling technologies in support of the Projects. Core C will also have an important function with respect to providing training for students and postdoctoral fellows with the use of the provided technologies and the proper methods of data analysis for those methods. Core C will closely coordinate its activities with those of Core B in support of the 4 Projects. The efficiencies and cost savings achieved by this Core will greatly accelerate the discovery process of each Project and by providing a central platform, upon which these analyses are accomplished, allow for inter-project data comparisons. This Core is also essential for enhanced rigor and transparency of the overall PPG.